The present invention relates to methods for operating a portable electronic device and to portable electronic devices.
Today's smart phones or tablet computers contain a couple of sensors such as, for example, a gyroscope or an acceleration sensor used for detecting an orientation of the device display for having the content to be displayed adapted to such orientation.
In general, chemical sensors are known for detecting an analyte in a gas or a fluid. In particular, metal-oxide sensors are chemical sensors known to be operated at elevated temperatures of a few hundred degrees Celsius. In order to achieve these temperatures in a sensitive layer of the chemical sensor a heater thermally coupled to the sensitive layer may be heated prior to and/or during taking a sensor reading. However, such metal-oxide sensors may suffer from drift even when the sensor is not operated and even in the absence of any chemical stimulus to the sensor. Drift may be understood as a variation in the sensor signal over time under identical environmental conditions. Drift may impact a transfer function of the sensor in form of an offset drift representing an additive component to the sensor signal, and/or in form of a sensitivity drift affecting an incremental gradient of the transfer function. Any drift in turn may impact the accuracy of the sensor signal.
Therefore it is desired to provide methods for operating a portable electronic device and to provide portable electronic devices comprising a chemical sensor in which an impact of a drift of the chemical sensor on an output of the chemical sensor may be reduced.